As explained on the company’s blog by Ken Case, The Omni Group’s founder and CEO:

…if you’re looking at purchasing the Mac app, it would be quite reasonable to wait until after the OmniFocus 2 debut so you know what’s coming before you make a decision. To make that wait easier for everyone, we’ve decided to post a temporary license key so you can all use [OmniFocus 1] between now and then without having to make a purchase.

Although OmniFocus is available on the Mac App Store, users interested in this free trial need to download the application binary from The OmniFocus website and then enter the following license information:

While only a limited trial, the offer is a great way for new users to check out an otherwise pricey (normally $80) but well-regarded application for free.

As mentioned above, OmniFocus 2 will be unveiled at Macworld/iWorld but will go through several rounds of private and public testing before a general release. Those interested in becoming private beta testers can sign up at The Omni Group site.